Process for preparing poly(allyltrialkylammonium) salt flocculants

A process for preparing a polyquaternary flocculant which process comprises:

• (1) preparing a preliminary free-radical polymer of a monomer selected from (i) the group consisting of N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-methyl, N-ethylacrylamide, N-methyl, N-ethylmethacrylamide, N, N-diethylacrylamide, N,N-diethylmethacrylamide, N-methyl, N-isopropylacrylamide, N-methyl, N-isopropylmethacrylamide, N-methyl, N-n-propylacrylamide, and N-methyl, N-n-propylmethacrylamide and (ii) mixtures thereof of a dialkylacrylamide of the structure:
• ##STR2## wherein R is hydrogen or methyl, R' and R" are alkyl groups such that the number of carbons provided by R' and R" is from 2 to about 4, said polymer having a molecular weight of at least about 5,000;
• (2) reducing the amide groups of the preliminary polymer to complete absence of carbonyl absorption in the infrared so as to provide the corresponding intermediate allyldialkylamine polymer;
• and (3) quaternizing the intermediate polymer using a stoichiometric excess of quaternization agent to ensure complete quaternization to provide the corresponding final poly(allyltrialkylammonium) flocculant in the form of a water-soluble salt, said polymer containing a total of 3 to about 5 carbons in said trialkyl groups.